1. Technical Field
The invention relates to a process for roughening metal surfaces in order to improve the adhesion of layers thermally sprayed thereon.
2. Background Art
WO 2007087989 A1 discloses a process for roughening metal surfaces in order to improve the adhesion of layers thermally sprayed thereon, wherein uniform grooves, e.g. rectangular or trapezoidal grooves, are introduced into the metal surface and resulting ridges are plastically deformed in order to form undercuts along the ridges. A disadvantage of this process is that the ridges are plastically deformed over their entire length. This requires a relatively large effort, it being possible to make the shape of the undercuts constant only with difficulty. Furthermore, the formation of the undercuts over the entire length of the grooves ensures that the grooves are filled completely by the spraying material only to a limited extent, since the adjacent undercuts form a narrow point through which only some of the spraying material can penetrate into a groove.